Fixed Condenser Boxes Manufacturer,Supplier and Exporter in India
Product Code : EL-SI-8085
Jlab Export is a leading Fixed Condenser Boxes Manufacturer,and suppliers in India
Fixed Condenser Boxes (code EL-SI-8085) are fixed-value capacitor boxes with two 4 mm socket terminals, used as known capacitances in AC bridge, RC timing and filter experiments in physics and electrical labs. Values from 0.01 to 2 mfd use paper polyester capacitors with a 250 V working voltage, and values from 5 to 40 mfd use electrolytic capacitors rated at 350 V. They are made by Jain Laboratory Instruments Pvt Ltd (JLab) at its works in Ambala, India.
Specifications
| Parameter | Detail |
|---|---|
| Terminals | Two 4 mm socket terminals |
| Values 0.01 to 2 mfd | Paper polyester capacitors; working voltage 250 V |
| Values 5 to 40 mfd | Electrolytic capacitors; working voltage 350 V |
| Capacitor types listed | Silver mica, paper polyester and metal film, with electrolytic capacitors for the higher values |
| Construction | Capacitors mounted on a plastic plate, fitted in a housing listed as “steel turf Non ABS Plastic” |
| Quality check | Each box is visually inspected before dispatch |
| Pack quantity | Each (sold individually) |
| Minimum order quantity | 10 units |
| Dispatch time | Usually 7–10 working days |
| Product code | EL-SI-8085 |
| Manufacturer | Jain Laboratory Instruments Pvt Ltd (JLab) — OEM |
| Country of origin | India (made in Ambala, Haryana) |
How Do They Compare with the JLab Four Dial Condenser Box?
| Model | Capacitance | Suited to |
|---|---|---|
| Fixed condenser boxes (EL-SI-8085) | Fixed value; 0.01–2 mfd paper polyester (250 V) or 5–40 mfd electrolytic (350 V) | A known standard or load capacitor that stays the same throughout the experiment |
| Four Dial Condenser Box | Four dials: 10 x 0.001, 10 x 0.01, 10 x 0.1 and 10 x 1 mfd; also offered as two-dial and three-dial boxes | Changing the capacitance in steps, for example while balancing a bridge |
Choose a fixed box when the experiment calls for one known capacitor, including the larger electrolytic values up to 40 mfd. Choose the dial box when students need to vary the capacitance during the experiment.
What Are Fixed Condenser Boxes Used For?
A boxed capacitor with 4 mm sockets can be patched into a circuit as quickly as a resistance box, so one set of boxes serves many practicals. The lower, paper polyester values suit AC work: as the standard capacitor in a De Sauty or Schering bridge, as the known arm when comparing two capacitances, and in RC filter and phase-shift circuits at audio frequencies. The larger electrolytic values give the long time constants needed in charging and discharging experiments, where students plot voltage or current against time and find the time constant RC, and they also serve as smoothing capacitors in rectifier and power-supply experiments.
Keep the applied voltage below the working voltage listed for the range — 250 V for the paper polyester values and 350 V for the electrolytic values. Electrolytic capacitors are polarised, so connect them the right way round and use them only where the voltage across them does not reverse; for AC bridge measurements use the non-polarised values. After any high-voltage experiment, discharge the capacitor through a resistor before touching the leads.
What to Specify When Ordering
- Capacitance values — list each value and how many boxes of it you need, within the 0.01–2 mfd and 5–40 mfd ranges.
- Working voltage — check that the listed 250 V or 350 V rating suits your circuits.
- Quantity — the minimum order is 10 units.
- Companion items — dial condenser boxes, inductance boxes or bridges from the list below can go in the same enquiry.
Frequently Asked Questions
What capacitance values are available?
The listing covers 0.01 to 2 mfd with paper polyester capacitors and 5 to 40 mfd with electrolytic capacitors. It does not list the individual standard values, so ask JLab which values can be supplied for your order.
What is the working voltage?
250 V for the 0.01–2 mfd values and 350 V for the 5–40 mfd values, as listed.
Can the electrolytic boxes be used in an AC bridge?
They are not the right choice. Electrolytic capacitors are polarised and are meant for circuits where the voltage does not reverse, such as charging, discharging and smoothing experiments; use the paper polyester values for AC bridges.
How are the boxes connected?
Each box has two 4 mm socket terminals, so standard 4 mm plug leads connect it to bridges, power supplies and meters.
How do they differ from the Four Dial Condenser Box?
A fixed box gives one capacitance; the four-dial box lets you set the capacitance on four decade dials. The fixed range also includes electrolytic values up to 40 mfd.
Who manufactures these condenser boxes?
Jain Laboratory Instruments Pvt Ltd (JLab) makes them at its works in Ambala, Haryana, India, and quotes for them directly.
OEM Manufacturer
JLab is the trading name of Jain Laboratory Instruments Pvt Ltd, a physics lab instruments manufacturer in India, incorporated in 2017 and based on Hargolal Road, Ambala, Haryana. The condenser boxes are assembled at JLab’s own works instead of being bought from a trader, so schools, colleges, dealers and importers order factory-direct, every box is visually inspected before dispatch, and repeat orders come from the same manufacturer. JLab exports worldwide and ships to buyers in every region — Lesotho in Southern Africa, Latvia in Northern Europe, Yemen in the Middle East, Samoa in Oceania and Bhutan in South Asia are examples. For tender supply, see the JLab lab tenders page.
Related Capacitance and Bridge Equipment
- Four Dial Condenser Box — a dial-type box for setting capacitance in decade steps.
- Fixed Inductance Boxes — fixed air-cored inductance coils for the same kind of AC circuit work.
- Schering Bridge — a capacitance bridge with built-in source and digital null detector.
- DE Sauty Bridge — for comparing the capacitance of two capacitors.
- Charging and Discharging of a Condenser — a board for studying charging, discharging and the time constant.
See the full Scientific Instrument range and the Indian Instruments section.
Request a Quote
JLab quotes directly as the manufacturer. Use the Add To Cart enquiry button on this page, or send the capacitance values, the number of boxes of each (minimum 10 units in total), any dial boxes or bridges you need and your delivery location through the contact page.
Last updated: 8 October 2026
